Building a set of solid arms doesn't always have to be a time drain in the gym. Instead of going through the normal rotation of dumbbells and barbell curls, it's important to switch up the structure of your program rather than the modalities.
Compound sets are a great tool to compile work in an effort to increase muscular fatigue for more hypertrophy. This bicep compound set is a combination of dumbbell curls and hammer curls different from how you'd normally mix them together.
Generally, you'll see two separate sets back to back, where here we're combining exercises in the single set in order to redistribute fatigue in the set. With muscle groups containing multiple heads, a little rotation can completely change the exercise.
Complete 4 sets of 15 where the first 10 reps are supinated dumbbell curls to focus on biceps brachii and brachialis. For the final 5 reps in the 15 rep set, rotate your hands to neutral to finish with hammer curls. This slight twist of the hand focuses more attention on the long head of the bicep and the brachioradialis in the forearm.